The use of casts for immobilizing a broken limb (broken arm, leg, etc.) is well-known. Casts are typically worn for many weeks until the broken limb heals. There is no effective way of washing the skin immediately underlying the cast and, after a period of time, bacteria build up under the cast creates skin irritation and a bad odor.
It is possible to reduce skin irritation and odor by circulating air between the cast and skin. U.S. Pat. No. 3,998,220 discloses a prior art venting device which generates a radially outward distribution of air under the cast from a disk-shaped fitting. An air coupling extending through the cast provides a means for supplying air to the fitting. Air flows from the fitting in a direction that is generally parallel to the skin surface.
Another related device is disclosed in U.S. Pat. No. 4,387,710. This patent describes a "passaged socket member" which is primarily imbedded within the cast. The socket member has a plurality of downwardly extending passageways which lead into a relatively thick "distributor layer." The distributor layer is described as being similar to the material used to make an abrasive-free cleansing pad. The distributor layer surrounds the limb and extends along the length of the cast. The socket member essentially communicates air through the wall of the cast into the distributor layer. The distributor layer creates enough of an airspace between skin and cast for air to thereafter circulate around the limb.
The present invention provides still another ventilation design having the same intended function as the devices disclosed in the above patents. However, the invention is much easier to install and much cheaper to make and use. It is also believed that it provides better circulation than the two prior devices just described. These differences, and others, will become more apparent after reviewing the following disclosure.